The absorption of a lipid, particularly cholesterol, is believed to be rate determined by a process wherein free cholesterol is converted to ester cholesterol by an ACAT (AcylCoA-Cholesterolacyltransferase) in small intestine epithelial cells. An ACAT inhibitory agent has been found to be useful as an anti-cholesterol agent in this respect. At present, several of these agents are being developed as pharmaceuticals.